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IV. The genera of Coleoptera studied chronologically 

 (1735-1801) . By G. R. Crotch, M.A. 



[Read 3rd January, 1870.] 



Having been engaged for some time in the preparation of 

 a complete list of the genera proposed in Zoology, com- 

 mencing naturally with the Entomological ones, I was 

 very glad to see in the "Proceedings/' a report of the 

 interesting discussion on Mr. Kirby's paper (Proc. Ent. 

 Soc. 1868, p. xlii) . With Mr. Cunning's note (pp. xlv- 

 xlviii) I agree entirely, and it has been suggested to me, 

 that a brief sketch of my work, so far as relates to the 

 Coleoptera, might not be uninteresting. All exact refer- 

 ences, etc., are omitted, to appear in the work itself. 



A genus appears to me to consist of but one species neces- 

 sarily, viz. its type; round which we arbitrarily group any 

 number of others, which may be removed at pleasure ; it 

 is therefore defined, not so much by characters, which vary 

 with our knowledge, but by the selection of a type-species; 

 from which I argue, that genera proposed in Catalogues, 

 on previously described species, are entitled to priority. 

 It is certainly far less productive of confusion, that a num- 

 ber of genera should be published, as in Dej can's Cata- 

 logue, with their species, than as in Latreille's " Precis," 

 with their characters only. 



In tracing the types of the various genera, I find that 

 Linnaeus apparently had no idea of types, and that his 

 genera varied considerably in their extent. I have traced 

 them from the first edition of the 8ystema Naturce in 1735, 

 which is, I think, the only consistent starting point, 

 though possibly not the most desirable one ; but certainly 

 Linngeus and his contemporaries "date the introduction 

 of genera from that work, and in the tenth edition he 

 mentions expressly, as a novel feature, that he now intro- 

 duces trivial names also ; (they had, however, been em- 

 ployed for five or six years in his various dissertations, 

 etc.) . It is, nevertheless, unfortunate that he should 

 have changed his opinions as he did. Geoffrey, in 1762, 

 seems to have had a clear conception of types, figuring 

 the typical species always, as did also Scheeffer four years 

 later, adding rough dissections; these authors, therefore, 

 settle most of the Linnaean genera. Fabiicius never 



TRANS. ENT. SOC. 1870. PART I. (mARCH.) 



